Python in a Nutshell

Name

proxy

Synopsis

proxy(x[,f])

Returns a weak proxy p of type ProxyType (CallableProxyType, if x is callable), with object x as the target. In most contexts, using p is just like using x, except that if you use p after x has been deleted, Python raises ReferenceError. p is never hashable (therefore you cannot use p as a dictionary key), even when x is. If f is present, it must be callable with one argument, and is the finalization callback for p (i.e., right before finalizing x, Python calls f ( p )). Note that when f is called, x is no longer reachable from p.